FR3071283A1 - CARDIAC PUMP EQUIPPED WITH INTERNAL BLADE TURBINE - Google Patents

Abstract

The invention relates to a pump designed for the circulation of a fluid, this pump comprising a housing (9) and a turbine (1) disposed in the housing and designed to perform rotational movements relative to the housing. According to the invention, the turbine comprises: - a body (2, 8, 81, 82) designed to perform rotational movements, - a hollow central portion (8a, 81a, 82a), passing through the body from one side to the other; for the passage of the fluid through the turbine, and - at least one blade (4, 5, 6, 7) disposed on the inner wall (3) of the body, in the hollow central portion, and adapted to circulate the fluid.

Description

Heart pump fitted with a turbine with internal blades.

The present invention relates to a pump for the circulation of a fluid. It finds a particularly interesting application in the field of regulation of blood flow. Indeed, such a pump can be implanted in the ventricle of a heart so as to increase the blood flow and adapt it to the patient's needs. Obviously, special attention must be paid to the characteristics of the pump. This pump must be biocompatible and provide a minimum of comfort to the patient.

The pump according to the invention can also be used outside the ventricle, in a vertical or horizontal position, whether or not connected to sensors.

Document W02017032510 is known, describing a pump provided with a turbine in the shape of a warhead. This turbine is equipped with several blades made on its surface. Although such a pump works with good performance, it nevertheless has some disadvantages such as the weight and the level of stress on blood cells.

The present invention relates to a new pump reducing the stress on the blood cells.

Another object of the invention is to limit friction inside the pump.

Another object of the invention is to reduce the energy consumption of the pump motor.

At least one of the objectives is achieved with a pump designed for the circulation of a fluid, this pump comprising:

- a housing, and

- a turbine arranged in the casing and designed to perform rotational movements relative to the casing.

According to the invention, the turbine comprises:

a body designed to perform rotational movements, a hollow central part passing through the body right through and intended for the passage of the fluid through the turbine, and

- At least one blade disposed on the internal wall of the body, in the hollow central part, and designed to circulate the fluid.

The pump according to the invention comprises a new type of turbine which is hollow and has internal blades, that is to say directed towards the central axis of rotation. Indeed, unlike known turbines or rotors which generally have a main body with blades arranged on the external surface, the present invention provides a hollow turbine with blades produced in its internal surface. The fluid is brought through the turbine, inside, directly, in a linear flow, with a minimum of friction.

Such an architecture makes it possible to reduce the weight of the turbine compared to a full turbine.

With such a pump implanted in a ventricle of a patient's heart, the patient's comfort is greatly improved. In addition, electricity consumption is also improved due to the low weight. This results in a more compact design of the energy source and / or an improved service life for such a pump.

As the fluid passes inside the turbine, the flow resistance is reduced.

Stress is reduced considerably, that is to say the shear stress on blood cells when the fluid is blood. The blood is therefore less degraded.

Advantageously, the casing and the turbine can constitute a part of a brushless motor, or “brushless” motor, the casing having the function of stator and the turbine having the function of rotor. One thus constitutes a synchronous machine with permanent magnets arranged in the rotor, while stator windings (windings) would be produced in the casing used as stator. In this embodiment, the control electronics is provided is arranged so as to act on the windings. This embodiment consists in having an integrated motor.

In an exemplary embodiment, the pump according to the invention may comprise a rod arranged in the central axis of the turbine so as to reduce the backflow of fluid. This rod is arranged in the center of the casing.

The rod can advantageously be fixed. Even if this is not a preferred embodiment, one can however imagine a rotating rod, integral or not with the turbine, fixed or not to the intake chamber.

For example, this rod can be fixed to said at least one blade or to the body of the turbine or by one end to an intake chamber which is integral with the casing. When the rod is attached to the intake chamber, the impeller can pivot around it.

The function of this rod is to contribute to the suppression of possible reflux of blood and to the prevention of the creation of vortex.

According to another embodiment of the invention, the pump can comprise a motor external to the turbine and driving a transmission shaft, the latter being disposed in the axis of rotation of the turbine and firmly connected by at least one radial stop. to the turbine. Unlike the previous case where the motor was finally integrated, in this embodiment, the motor is outside the turbine and has a shaft which drives the turbine in rotation. The shaft is securely attached to the turbine by edges which have a profile allowing easy passage of the fluid.

Preferably, the drive shaft can be both connected to the upstream end and to the downstream end of the blade.

According to an advantageous characteristic of the invention, the pump also comprises:

- an Inductor with guide vanes to make the flow of the fluid linear; this inductor being arranged upstream of the turbine with respect to the direction of circulation of the fluid;

- a diffuser equipped with diffusion vanes to make the flow of fluid linear and increase the pressure of the fluid; this diffuser being arranged downstream of the turbine so as to discharge the fluid from the turbine to the outside by transforming the kinetic energy created by the turbine into potential energy; and

- a rectifier with rectifier vanes and an outlet orifice of diameter smaller than the inlet diameter of the rectifier, the rectifier vanes directing the fluid, coming from the diffuser, towards the orifice so as to increase the speed and give to the fluid a predetermined profile at the outlet of the orifice.

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Linear fluid flow as defined here is as opposed to a swirling flow. This linear flow can be laminar.

The rectifier (“straightener” in English) according to the invention makes it possible to create a flow by concentrating the fluid so as to obtain high speed values at the outlet of the pump. In general, the vascular system of a heart has fairly high vascular resistances. An effective pump is a pump capable of propelling blood through the valves with sufficient pressure to overcome these vascular resistances. The pressure at the outlet of the pump is essential compared to the outlet speed which with the pump according to the invention can reach the maximum speed of 3 m / s.

In other words, the rectifier allows to channel the fluid, to create a profile allowing to have a maximum speed at a point, i.e. aligned with the aortic valve, so as to expel the flow in a laminar way. This avoids the creation of vortices at the outlet of the pump. The diameter of the outlet is smaller than the internal diameter of the housing. Its small outlet diameter, for example a half or a third of the internal diameter of the housing, makes it possible to adjust the parameters of pressure, between 80 and 200 mmHg, and speed, between 1 and 3 m / s, while avoiding creation of a current at negative speed (in the opposite direction due to lack of pressure and homogeneity of the output flow).

The diffuser and rectifier assembly according to the invention therefore makes it possible to make the pump effective. The rectifier diffuses the fluid directly towards the outlet in the ambient medium by creating a flow. This ambient medium can advantageously be said fluid, which is preferably blood.

The inductor according to the invention avoids the phenomenon of cavitation, that is to say the creation of bubbles in the fluid.

It is important to note that this pump is perfectly suited for operation in a vertical arrangement, or slightly tilted, that is to say inclined between 0 and 5 degrees relative to the vertical axis. The pump according to the invention can also operate lying down like most of the pumps of the prior art.

The pump according to the invention may also comprise an intake chamber provided with lateral openings so that the fluid can penetrate radially and then engage in the axis towards the inductor. This intake chamber can be of cylindrical shape comprising on its upper part downstream of said openings, a receptacle for accommodating the inductor. The inlet chamber and the inductor can constitute two parts intended to be firmly secured to one another or else be designed as a single piece. The casing can also be associated with them so as to constitute a single piece.

According to an advantageous characteristic of the invention, the blade is of the helical type. The function of such a blade is to suck the fluid and pass it through the interior of the turbine.

This blade can be more or less marked, that is to say it can be one or more inserts relative to the turbine or else protuberances, grooves or undulations forming an integral part of the turbine, produced on its inner wall.

The helical blade is like a serpentine on the internal wall of the turbine so that the angle of attack of the helical blade decreases as one moves from the upstream end of the turbine towards the 'downstream end; the angle of attack being defined as the angle between the axis of rotation of the turbine and a vector tangent to the external surface of the helical blade.

According to another advantageous characteristic of the invention, the pump comprises several blades distributed over the internal wall of said body. These blades are arranged to apply a minimum of stress to the fluid and optimize the suction.

According to one embodiment of the invention, the blade consists of several turns with increasing winding pitch and tending towards infinity.

Advantageously, the hollow central part of the turbine can be of cylindrical shape. That is to say that the internal wall of the turbine may have the profile of a straight cylinder, of circular section for example, and / or the fixed or variable radial thickness of the blade is such that the empty space (filled with air or fluid) has the profile of a straight cylinder, with circular section for example.

According to one embodiment of the invention, the hollow central part can be of flared shape, the most open end being arranged downstream in the direction of circulation of the fluid.

... ₆ ...

The turbine outlet is larger than the inlet.

According to another embodiment of the invention, the hollow central part of the turbine is oblong, the most open end being arranged downstream in the direction of circulation of the fluid.

Preferably, for efficient rotation, the turbine body may have an outside shape of the right cylinder type with circular section.

According to one embodiment, the radial thickness of the blade can be fixed or variable over the entire length between the upstream end and the downstream end of this blade, that is to say over the entire length of the blade . If it remains constant, the blades then delimit an area which has a shape substantially identical to the shape of the hollow part.

According to an advantageous characteristic of the invention, the hollow central part and said at least one blade have a profile of centrifugal type on the upstream side, of mixed type in the central part, and of axial type on the downstream side.

The pump according to the invention integrates the characteristics at the same time:

a centrifugal type pump, that is to say a radial acceleration for the part of the fluid taken up by the blades and arriving axially, to do this the lower part of the blades, in particular helical, can have a pronounced angle, on the order of 45 degrees, for example between 40 and 50 degrees, relative to the axis of rotation of the turbine, of a mixed type pump, that is to say a slope or a less pronounced curvature of the turns of the helical blades for example, and of an axial type pump, the fluid being conducted in a direction parallel to the axis of rotation of the turbine.

This configuration makes it possible to limit the shear stresses (“shear stress” in English) which can cause hemolysis, that is to say a destruction of the red blood cells. Even with a high flow, when the red blood cells are destroyed, oxygen does not reach the cells.

The shear forces are created by the vortex of blood entering and leaving the pump. The pump according to the invention avoids vortices by a call for blood by using a centrifugal type structure and an axial delivery.

According to an advantageous characteristic of the invention, a first zone of said at least one blade is dimensioned so that the fluid reaches a specific speed between 0 and 1.2; this first zone being on the upstream side of the blade.

Furthermore, a second zone of said at least one blade is dimensioned so that the fluid reaches a specific speed of between 1 and 2.2; this second zone being at the middle of the blade.

Finally, a third zone of said at least one blade is dimensioned so that the fluid can reach a specific speed greater than 2.2; this third zone being on the downstream side of the blade. It is a specific speed value allowing to classify the centrifugal, mixed or axial structures respectively.

Other advantages and characteristics of the invention will appear on examining the detailed description of a mode of implementation in no way limiting, and the appended drawings, in which:

FIG. 1 is a schematic view of a turbine with internal blades according to the invention,

FIGS. 2a, 2b and 2c are diagrams illustrating the arrangement of the helical blades inside the turbine according to the invention,

FIGS. 3a, 3b and 3c are schematic sectional views illustrating a “brushless” DC motor with different configurations of the hollow central part of the turbine according to the invention,

FIG. 3d is a schematic sectional view illustrating an engine of the type described in FIGS. 3a to 3c with a rod placed in the center of the turbine,

FIG. 3e is a schematic view of an intake chamber carrying the rod of FIG. 3d,

FIG. 4 is a schematic view by transparency of the interior of a pump incorporating a turbine according to the invention,

FIG. 5 is an exploded view of the pump incorporating a turbine according to the invention,

FIG. 6 is a sectional view of the pump in FIGS. 4 and 5,

FIG. 7 is a schematic view in longitudinal section of a pump according to the invention,

... ₈ ...

FIG. 8 is a perspective view of an intake chamber according to the invention,

FIG. 9 is a perspective view of an inductor to be inserted into the intake chamber according to the invention,

FIG. 10 illustrates different sectional and perspective views of a casing intended to contain the turbine according to the invention,

FIG. 11 is a perspective view of a diffuser according to the invention,

FIG. 12 is a perspective view of a rectifier according to the invention,

FIG. 13 is a perspective view of a turbine fixed to a transmission shaft of an engine according to the invention,

FIG. 14 is an exploded view of the pump integrating the turbine of FIG. 13 according to the invention,

FIG. 15 is a schematic view illustrating a fixing between a transmission shaft and the turbine of FIG. 13 according to the invention,

FIG. 16 is a schematic sectional view revealing the interior of a pump integrating the turbine of FIG. 13 according to the invention,

FIG. 17 is a schematic view of a pump according to the invention comprising a motor whose transmission shaft is connected to the turbine of FIG. 13 according to the invention,

FIGS. 18 and 19 are schematic views of an inductor according to the invention, and

Figures 20 and 21 are schematic views of a rectifier according to the invention.

The embodiments which will be described below are in no way limiting; it will be possible in particular to implement variants of the invention comprising only a selection of characteristics described subsequently isolated from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from in the prior art. This selection comprises at least one preferably functional characteristic without structural details, or with only a part of the structural details if this part only is sufficient to confer a technical advantage or to differentiate the invention from the state of the prior art.

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In particular, all the variants and all the embodiments described are designed to be combined with one another in all combinations where nothing is technically opposed to it.

In the figures, the elements common to several figures keep the same reference.

In Figure 1 there is a turbine 1 according to the invention. In the example described without limitation, it is a body 2 in the form of a long, hollow cylinder, the internal wall 3 of which comprises several blades 4, 5 6 and 7. Such a turbine can advantageously be used in a pump immersed in a fluid.

The blades have the function of passing the fluid through the turbine. The orientation and sizing of the blades are provided so that the fluid is sucked in and then propelled after passing through the turbine which is in rotation.

Unlike systems of the prior art where the fluid circulates outside the turbine, the present invention provides a hollow turbine circulating the fluid inside.

FIG. 2b illustrates the four helical blades 4 to 7, which start from one end of the turbine, fit into helical lines without ever crossing each other, and arrive at the other end.

In the example of FIG. 2b, the hollow central part of the body 2 has a concave flared shape. The upstream end 2a has a smaller opening than the downstream end. Figure 2a is a front view of the end 2a while Figure 2c is a front view of the end 2c. The helical blades follow the shape of the internal wall 3.

The hollow central part can have other shapes such as those shown in Figures 3a to 3c without limitation.

In Figure 3a, a turbine 8 is shown in section. It is a cylinder having a hollow central part 8a of flared shape such as a funnel. A blade 4 is schematically illustrated. Of course, several blades 4, 5, 6 or 7 can be arranged. This turbine 8 is designed to be rotated relative to a casing 9 surrounding it. Ideally, the casing 9 is a stator comprising magnetic windings 10. The latter can cooperate magnetically with permanent magnets 11 disposed inside or on the external surface of the turbine. Means

- 10 electronics (not shown) are provided to control the windings 10 so as to activate the turbine. The assembly constitutes a “brushiess” type motor. The air gap between the turbine and the casing is straight, it fits into a straight cylinder, but it can be of another non-straight shape, flared or not.

In FIG. 3b, the hollow central part Sla has an oblong shape as in FIG. 2b but with a downstream end which closes slightly.

In FIG. 3c, the hollow central part 82a has the shape of a straight cylinder.

In the three figures 3a, 3b and 3c we find the same casing 9 as well as the same magnetic elements making it possible to constitute a “brushiess” type motor.

It has been found that the arrangement of a rod inside the turbine makes it possible to improve the flow of blood when the pump is in operation, that is to say the turbine rotating relative to the casing. Figure 3d illustrates an exemplary embodiment of a pump in which a rod 88, straight, is disposed in the axis of the turbine. In the example described in FIG. 3d, the pump comprises an intake chamber 85, 86 which can be seen in FIG. 3e. This intake chamber comprises a base 85 carrying spacers 86 connected to a crown 89 for fixing to the casing 9. The passages between the crown 89 and the base 85 allow the entry 87 of the fluid or blood towards the interior of the turbine along the rod 88, under the action of the blades 4, 5, 6, 7. This rod 88 may have a height such that its free end (upper in FIG. 3d) is located inside the turbine , beyond the turbine, flush with the upper end of the turbine or the casing.

The rod 88 is fixed at one end to the base 85. Other modes of arrangement of the rod can be envisaged, such as for example connected only to the turbine and no longer to the base 85. Indeed, the rod 88 can be fixed to the body 82 of the turbine or to one of the blades 4, 5, 6, 7 for example from the top, at the upper end (relative to the representation of FIG. 3d). In this case, the lower end of the rod 88 may preferably be free or else fixed to a blade, to the body of the turbine or to the intake chamber.

In particular in addition to the above and in a manner compatible with other embodiments, the turbine may be contained in the casing by means of flanges 83 and / or 84 produced for example at the ends of the casing and extending towards the inside. Rolling mechanisms can be provided between the turbine and the flanges. Other means can be provided to keep the turbine rotating in the housing without contact. One can in particular envisage a mechanism by levitation, by fluid, by magnetization, etc., with or without the edges 83 and / or 84.

Figures 1 to 3 describe in particular a turbine and a casing which, associated with fluid inlet and outlet components and with electronic components, make it possible to constitute a pump.

We will now describe with reference to Figures 4 to 6, a pump according to the invention incorporating a turbine as described above.

In FIG. 4, there is a global view in transparency of a pump 12. This pump is in the overall form of a cylinder with circular section, intended to suck a fluid such as blood and to discharge it so as to favor the blood circulation. Such a pump is intended to be installed in a body, in particular for ventricular assistance. Its length is approximately 61.8mm, the diameter of the casing 9 is approximately 17-20 mm, while the lower part 13 has a diameter of approximately 15-20 mm.

The pump according to the invention can advantageously, but not only, be used in vertical positioning, that is to say the casing 9 vertically and above the bottom part 13.

According to the invention, the inlet chamber 13 has the function of bringing the fluid, in particular blood, through the gills or openings 13a under the action of a suction coming from inside the casing 9. The fluid is then discharged through an opening at the upper end of the casing.

The upper stages of the intake chamber 13 comprise the turbine 1 intended to move in rotation inside the casing 9, and outlet elements such as a diffuser 14 and a rectifier 15. The turbine 1 visible in the exploded view of FIG. 5 presents a hollow central part of oblong, oval shape or an elongated or stretched warhead on one end. The hollow central part delimited by the internal wall 3 has a diameter of the circular section (radial section) which increases from its lower part to the upper part.

In FIG. 5, the exploded view makes it possible to understand that the two components generally visible from the outside are the casing 9 having a reduced lower part intended to be inserted on the upper part of the intake chamber 13. The turbine 1 is inserted inside the casing 9, in the central part. The diffuser 14 and the rectifier 15 fits into the casing 9 through the upper end.

In FIG. 6, a clear distinction is made between the helical blades made on the internal wall 3.

The different parts of the pump can be designed by molding, 3D printing, machining or others. Advantageously, between three and five blades are produced.

In Figure 7, arrowsl6 indicate the path of the fluid inside the pump. The fluid enters through the openings 13a of the intake chamber and is then accelerated axially in the turbine under the rotary action of the blades. Each helical blade is a serpentine of constant or variable thickness over the entire length so that the shape of the interior space conforms or not to the shape of the internal wall 3. This interior shape is oblong or of warhead type.

The axial turbine according to the invention is intended for continuous operation.

The circulation of the fluid takes place in a linear flow which occupies the entire central space of the turbine. The flow is thus high and the fluid, when it is especially blood, undergoes the least possible shock, therefore the least possible stress on the cells.

In Figure 8 we see in more detail the inlet chamber 13 consisting of a lower part 13b, an upper part 13c, the two parts being connected by radial guides 13d delimiting the openings 13a towards the inside of the admission room.

The lower part 13b is a cylinder of circular section, with a thick wall so that the central part is a tunnel 13e. In the example in Figure 8, the diameter of the tunnel is 6 mm.

The radial guides 13d are three plates inscribed in planes which intersect on the axis of the intake chamber. The outer face of each plate 13d is flush with the lateral outer surface of the upper part 13c. The central area of the upper part containing the axis of the chamber

- 13 intake is empty for the passage of fluid. This central zone constitutes a tunnel with a diameter greater than the diameter of the tunnel 13e.

The upper part 13c is in the form of a cylinder having two different thicknesses, a first thickness on the upstream side, that is to say on the side in contact with the radial guides 13d, and a second thickness, less than the first, on the downstream side. Between the two layers is a 13f step. With such an arrangement, an Inductor 17 as described in FIG. 9 can be inserted and fixed inside the intake chamber 13 in the very thick part 13c. During insertion, this inductor 17 can come to rest on the ends of the guides 13d. The dimensions of the inductor 17 are such that a fols inserted, its upper part is flush with the step 13f. One can envisage other embodiments such as for example a single part made up of the elements 13c and 17, or else 13 and 17. The inductor 17 is a hollow cylinder comprising radial guides 17a, for example four in number up to 'to six, over the entire height of the cylinder and forming part of concurrent radial planes in the center of the cylinder. The inductor 17 serves as a fluid entry guide. It limits cavitation in the upper floors. The guides 17a produce a laminar flow so that the turbulent nature of the fluid is considerably reduced. This makes it possible to slow down and reduce the generally rapid deterioration of the turbine, by limiting the attacks of the fluid on the blades of the turbine.

It will be noted that only the upper part 13c of the intake chamber can be associated with the rest of the pump when the casing and the turbine constitute a “brushless” motor.

In FIG. 10, there is a more detailed distinction between the casing 9 consisting of a main body 9a and a secondary body 9b. The main body 9a is an elongated cylinder, the secondary body being a cylinder whose outside diameter is less than the outside diameter of the main body. The secondary body 9b is shaped so as to fit and be kept fixed in the upper part 13c of the intake chamber.

Preferably the lower end of the secondary body 9b abuts on the step 13f, visible in FIG. 8.

The internal shape of the casing 9 is complementary to the external shape of the turbine, with an air gap between them. The upper end 9d of the casing 9 has an inner diameter greater than the diameter of the

... 14 lower part 9c; the lower part housing the turbine. The diffuser 14 and the rectifier 15 are housed in this upper part 9d of the casing 9. The turbine therefore does not occupy the entire length of the casing. The turbine can be held in the housing by using bearings and seals.

The turbine according to the invention makes it possible to communicate the kinetic energy to the fluid by its particular shape. It changes the speed of the fluid without shearing and also increases its pressure. To do this, the pump outlet elements help to increase the pressure by presenting a reduced outlet port as well as specific shapes.

In FIG. 11, we see the diffuser 14 which is a cylinder intended to come over the head of the turbine. The diffuser comprises guide blades oriented 14a in the direction of delivery of the fluid supplied by the turbine. The orientation of the guide blades makes it possible to transform part of the kinetic energy of the fluid into pressure which is potential energy. The thickness of the guide blades can be fixed along the diffuser or else variable.

In Figure 12, we see a rectifier 15 having the role of guiding the delivery of the fluid by creating a laminar flow so as to eliminate any turbulence. It is an open cylinder 15a on its base for receiving the fluid coming from the turbine via the diffuser 14. It has an orifice 15b of smaller diameter compared to the diameter of the opening 15a on its base.

There is an inner wall 15d of concave conical shape from the opening 15a on its first half and then convex conical on its second half towards the orifice 15b. The fluid is pressurized when pushed towards the orifice of small diameter.

There are also three guide blades 15c inscribed in radial planes which compete in the center of the rectifier. Each blade is a blade of thicker width on the side of the wall than on the side of the center of the cylinder. The width therefore becomes thinner as it moves away from the wall of the cylinder.

In the configuration described, for each guide blade, the profile of the side facing the axis of rotation of the cylinder is curved, in particular in an arc of a circle, so that the guide blades approach each other at level of the orifice and are further away from the side of the opening 15a.

The turbine 1 according to the invention forms with the casing 9 and electronic and magnetic elements, a "brushless" motor capable of circulating the fluid.

FIG. 13 shows another turbine 18 according to the invention. This turbine 18 can be identical to the turbine 1 described above, with or without the magnetic components (windings and permanent magnets and any other element making it possible to constitute a motor). When it does not have permanent magnets, the turbine body can be lighter and thinner in design.

The notable difference with the turbine 1 is the presence here of a transmission shaft 19 which is fixed to the turbine 18. This transmission shaft 19 is inserted in the axis of the turbine 18 and has a greater length so that it exceeds the turbine through the lower part (upstream) and does not exceed the upper end (downstream) of the turbine. The upper end of the drive shaft 19 has four edges or rods 20, each connected to the end of a blade. As can be seen in FIG. 15, provision is also made for the drive shaft to be fixed at the lower end (upstream) of the turbine 18, directly or via edges at the lower ends of the blades. In this way, the transmission shaft is securely connected to the turbine and the rotation of this shaft causing the rotation of the turbine. This shaft 19 may be the transmission shaft of an external motor or else an independent rod capable of coming into engagement with an motor.

Figure 14 is an exploded view in which there are the same elements as in Figure 5 but with a turbine 18 in place of the turbine

1. The transmission shaft passes in the axis of revolution of the inductor 17 and of the intake chamber 13. The casing 9 can also be different, more simplified, when it does not include magnetic windings for constitute a stator.

It is possible to envisage a turbine 18 and a casing 9 controlled both by an external motor via the transmission shaft 19 and by an asynchronous or “brushless” motor constituted by the turbine 18 and the casing 9.

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Note that the external motor can also advantageously be of the “brushless” type.

In FIG. 16, the arrows 21 represent the circulation of the fluid such as the blood inside the pump. The blood arrives radially through the openings 13a of the intake chamber, then is oriented axially along the transmission shaft 19 via the inductor 17, the transmission shaft being in rotation as well as the turbine 18. The blood is then evacuated via the diffuser 14 and the rectifier 15.

The blood flow is then evacuated to the outside via the diffuser 14 and the rectifier 15 which by its outlet orifice creates a laminar flow of high pressure. The pump is designed to operate in immersion at a frequency ranging from 500 to 10,000 rpm.

FIG. 17 shows a pump according to the invention integrating the turbine 18 as well as an external “brushless” motor 22. The latter is firmly connected to the transmission shaft 19 by means of a motor shaft 23. Preferably this connection is removable so that it is possible to easily replace the motor in the event of failure. It can be a connection by clip, by screwing or other. This connection can also be the only link between the motor and the rest of the pump.

In FIGS. 18 and 19, there is a schematic representation of an individual inductor 24 in FIG. 18 and a schematic representation only of the blades 25 of this inductor in FIG. 19. This inductor can be designed individually. It will then be firmly fixed in an intake chamber. It can also be carried out directly in an intake chamber or in a turbine housing; in this case it is the blades which are produced on the internal wall of the intake chamber or of the turbine housing. The central zone of the inductor is left free for the passage of the fluid. In FIG. 19, the central zone of the inductor represents the flow of the fluid.

In general and for all of the embodiments, the blades of the inductor according to the invention are thicker upstream than downstream in the direction of movement of the fluid. The progression of the thickness can be linear, but preferably discontinuous: a linear progression until reaching a certain thickness, then the thickness remains constant over the rest of the length of the blade. Furthermore, the blades can also be thicker at the point of connection with the cylinder 26 which carries them than at the central end. An angle is also provided between the radial section of each blade and the radius of the cylinder 26 carrying the blades.

Figures 20 and 21 illustrate a front view and a rear view of a rectifier according to the invention. This rectifier can be produced individually and then fixed in the pump casing or else directly produced on the internal wall of the casing, that is to say a wall identical to the internal wall of the cylinder 27 of the rectifier and of the blades. designed directly on this wall. The blades 28 are thicker upstream than downstream in the direction of circulation of the fluid. The progression of the thickness can be linear. In Figure 20 is illustrated the downstream side of the rectifier, that is to say the place through which the fluid exits. In Figure 21 is illustrated the upstream side of the rectifier, the fluid inlet. On the latter side, the blades 28 leave a larger central space than on the downstream side, the blades and the internal wall 29 of the cylinder 27 carrying the blades being designed so as to guide the fluid towards the outlet orifice 30 which is more narrower than the rectifier input.

Of course, the invention is not limited to the examples which have just been described and numerous modifications can be made to these examples without departing from the scope of the invention.

The pump according to the invention can easily be implanted in a heart by its small size because of its particular design allowing a high pressure while preserving the quality of the blood.

The pump according to the invention consumes little because it operates according to the physiological heart rate: an oscillating flow.

The pump according to the invention operates by propelling: the rhythm is pulsed.

The pump according to the invention makes it possible to limit the contact surface with the fluid as well as the resistance of the turbine to the flow. We also limit the stresses on blood cells (“shear stress”).

With a hollow turbine according to the invention, there is a considerable gain in weight, which limits the energy necessary for its operation. This also makes it possible to increase the flow volume of the flow as well as the flow rate.

These advantageous characteristics make it possible to improve the overall comfort of a patient who would wear such a pump.

- 18 The pump according to the invention is advantageously designed to operate vertically, the rotor being arranged vertically, the fluid enters via the inductor, passes through the rotor and then exits from above via the diffuser and the rectifier. Most of the prior art pumps operate horizontally. It is the inlet and outlet capacity which allows the vertical operation of the pump according to the invention. Such a pump, placed in a left or right ventricle for example, has the advantage of having an inlet and an outlet directly into this ventricle. This avoids the presence of an inlet and / or outlet tube as there are on other devices of the prior art.

Claims (19)

1. Pump designed for the circulation of a fluid, this pump comprising: a housing (9), - a turbine (1) disposed in the casing and designed to perform rotational movements relative to the casing, characterized in that the turbine (1) comprises: - a body (2, 8, 81, 82) designed to perform rotational movements, - a hollow central part (8a, Sla, 82a), passing right through the body and intended for the passage of the fluid through the turbine, and at least one blade (4, 5, 6, 7) disposed on the internal wall (3) of the body, in the hollow central part, and designed to circulate the fluid. 2. Pump according to claim 1, characterized in that the casing (9) and the turbine (1) constitute a part of a brushless motor, or "brushless" motor, the casing having the stator function and the turbine having the rotor function. 3. Pump according to claim 2, characterized in that the casing (9) comprises stator windings (10) and the turbine comprises permanent magnets (11). 4. Pump according to any one of the preceding claims, characterized in that it comprises a rod (88) disposed in the central axis of the turbine (8, 81, 82) so as to reduce the backflow of fluid. 5. Pump according to claim 4, characterized in that the rod (88) is fixed to said at least one blade (4, 5, 6, 7) or to the body (2, 8, 81, 82) of the turbine or by one end to an intake chamber (85) which is integral with the casing (9). 6. Pump according to claim 1, characterized in that it comprises an external motor (22) to the turbine and driving a transmission shaft (19), the latter being disposed in the axis of rotation of the turbine and securely connected by at least one stop (20) radial to the turbine. 7. Pump according to claim 6, characterized in that the transmission shaft (19) is connected to the upstream end and to the downstream end of the blade. 8. Pump according to any one of the preceding claims, characterized in that it further comprises: - an inductor (17) provided with guide vanes to make the flow of the fluid linear; this inductor being arranged upstream of the turbine with respect to the direction of circulation of the fluid; - a diffuser (14) provided with diffusion vanes to make the flow of fluid linear and increase the pressure of the fluid; this diffuser being arranged downstream of the turbine so as to discharge the fluid from the turbine to the outside by transforming the kinetic energy created by the turbine into potential energy; and - a rectifier (15) with rectifier vanes and an outlet orifice of diameter smaller than the inlet diameter of the rectifier, the rectifier vanes directing the fluid, coming from the diffuser, towards the orifice so as to increase the speed and give the fluid a predetermined profile at the outlet of the orifice. 9. Pump according to claim 8, characterized in that it further comprises an inlet chamber (13) provided with lateral openings (13a) so that the fluid can penetrate radially and then engage in the axis towards l 'inductor. 10. Pump according to claim 9, characterized in that the intake chamber (13) is of cylindrical shape comprising on its upper part downstream of said openings, a receptacle for receiving the inductor (17). 11. Pump according to any one of the preceding claims, characterized in that the blade (4, 5, 6, 7) is of helical type. 12. Pump according to any one of the preceding claims, characterized in that it comprises several blades distributed over the internal wall (3) of said body. 13. Pump according to any one of the preceding claims, characterized in that the blade consists of several turns with increasing winding pitch and tending towards infinity. 14. Pump according to any one of the preceding claims, characterized in that the hollow central part (82a) of the turbine is of cylindrical shape. 15. Pump according to any one of claims 1 to 13, characterized in that the hollow central part (8a) is of flared shape, the most open end being arranged downstream in the direction of circulation of the fluid. 16. Pump according to any one of claims 1 to 13, characterized in that the hollow central part (Sla) of the turbine is of oblong shape, the most open end being arranged downstream in the direction of circulation of the fluid . 17. Pump according to any one of the preceding claims, characterized in that the said body (2, 8, 81, 82) has an external shape of the straight cylinder type with circular section. 18. Pump according to any one of the preceding claims, characterized in that the radial thickness of the blade is fixed or variable over the entire length between the upstream end and the downstream end of this blade. 19. Pump according to any one of claims 1 to 13, characterized in that the hollow central part (8a, Sla, 82a) and said au H minus one blade (4, 5 _f 6, 7) have a centrifugal type profile on the upstream side, a mixed type in the central part, and an axial type on the downstream side.